001////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code for adherence to a set of rules.
003// Copyright (C) 2001-2017 the original author or authors.
004//
005// This library is free software; you can redistribute it and/or
006// modify it under the terms of the GNU Lesser General Public
007// License as published by the Free Software Foundation; either
008// version 2.1 of the License, or (at your option) any later version.
009//
010// This library is distributed in the hope that it will be useful,
011// but WITHOUT ANY WARRANTY; without even the implied warranty of
012// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
013// Lesser General Public License for more details.
014//
015// You should have received a copy of the GNU Lesser General Public
016// License along with this library; if not, write to the Free Software
017// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
018////////////////////////////////////////////////////////////////////////////////
019
020package com.puppycrawl.tools.checkstyle.checks.naming;
021
022import java.util.regex.Pattern;
023
024import com.puppycrawl.tools.checkstyle.StatelessCheck;
025import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
026import com.puppycrawl.tools.checkstyle.api.DetailAST;
027import com.puppycrawl.tools.checkstyle.api.TokenTypes;
028
029/**
030 * <p>
031 * Ensures that the names of abstract classes conforming to some
032 * regular expression and check that {@code abstract} modifier exists.
033 * </p>
034 * <p>
035 * Rationale: Abstract classes are convenience base class
036 * implementations of interfaces, not types as such. As such
037 * they should be named to indicate this. Also if names of classes
038 * starts with 'Abstract' it's very convenient that they will
039 * have abstract modifier.
040 * </p>
041 *
042 * @author <a href="mailto:simon@redhillconsulting.com.au">Simon Harris</a>
043 * @author <a href="mailto:solid.danil@gmail.com">Danil Lopatin</a>
044 */
045@StatelessCheck
046public final class AbstractClassNameCheck extends AbstractCheck {
047
048    /**
049     * A key is pointing to the warning message text in "messages.properties"
050     * file.
051     */
052    public static final String MSG_ILLEGAL_ABSTRACT_CLASS_NAME = "illegal.abstract.class.name";
053
054    /**
055     * A key is pointing to the warning message text in "messages.properties"
056     * file.
057     */
058    public static final String MSG_NO_ABSTRACT_CLASS_MODIFIER = "no.abstract.class.modifier";
059
060    /** Whether to ignore checking the modifier. */
061    private boolean ignoreModifier;
062
063    /** Whether to ignore checking the name. */
064    private boolean ignoreName;
065
066    /** The regexp to match against. */
067    private Pattern format = Pattern.compile("^Abstract.+$");
068
069    /**
070     * Whether to ignore checking for the {@code abstract} modifier.
071     * @param value new value
072     */
073    public void setIgnoreModifier(boolean value) {
074        ignoreModifier = value;
075    }
076
077    /**
078     * Whether to ignore checking the name.
079     * @param value new value.
080     */
081    public void setIgnoreName(boolean value) {
082        ignoreName = value;
083    }
084
085    /**
086     * Set the format for the specified regular expression.
087     * @param pattern the new pattern
088     */
089    public void setFormat(Pattern pattern) {
090        format = pattern;
091    }
092
093    @Override
094    public int[] getDefaultTokens() {
095        return getRequiredTokens();
096    }
097
098    @Override
099    public int[] getRequiredTokens() {
100        return new int[] {TokenTypes.CLASS_DEF};
101    }
102
103    @Override
104    public int[] getAcceptableTokens() {
105        return getRequiredTokens();
106    }
107
108    @Override
109    public void visitToken(DetailAST ast) {
110        visitClassDef(ast);
111    }
112
113    /**
114     * Checks class definition.
115     * @param ast class definition for check.
116     */
117    private void visitClassDef(DetailAST ast) {
118        final String className =
119            ast.findFirstToken(TokenTypes.IDENT).getText();
120        if (isAbstract(ast)) {
121            // if class has abstract modifier
122            if (!ignoreName && !isMatchingClassName(className)) {
123                log(ast.getLineNo(), ast.getColumnNo(),
124                    MSG_ILLEGAL_ABSTRACT_CLASS_NAME, className, format.pattern());
125            }
126        }
127        else if (!ignoreModifier && isMatchingClassName(className)) {
128            log(ast.getLineNo(), ast.getColumnNo(),
129                MSG_NO_ABSTRACT_CLASS_MODIFIER, className);
130        }
131    }
132
133    /**
134     * Checks if declared class is abstract or not.
135     * @param ast class definition for check.
136     * @return true if a given class declared as abstract.
137     */
138    private static boolean isAbstract(DetailAST ast) {
139        final DetailAST abstractAST = ast.findFirstToken(TokenTypes.MODIFIERS)
140            .findFirstToken(TokenTypes.ABSTRACT);
141
142        return abstractAST != null;
143    }
144
145    /**
146     * Returns true if class name matches format of abstract class names.
147     * @param className class name for check.
148     * @return true if class name matches format of abstract class names.
149     */
150    private boolean isMatchingClassName(String className) {
151        return format.matcher(className).find();
152    }
153}